The field of the invention is collapsible furniture.
Folding chairs are relatively popular, because they can be stored with considerably reduced space requirements when compared to non-folding chairs. Nevertheless, folding chairs still require relatively large space, since the dimension of the folding chair is generally reduced only along one space coordinate (e.g., reduced length). To further reduce the space requirement, collapsible chairs have been developed, in which further size reduction is achieved by folding the chair along at least two space coordinates (e.g., length and width). Various collapsing chairs are known in the art.
For example, Cook et al. describes in U.S. Pat. No. 5,921,621 a collapsible chair with a foldable backrest, in which the chair has four legs that support the corners of a flexible square seat. The legs are movably attached to each other at about their respective midpoints, and the seat is collapsed in width and depth by turning the legs around the midpoint. While Cooks chair is relatively easy to unfold and collapse, Cooks chair provides relatively little stability and is prone to tipping over.
Improved stability can be achieved by including slidable cross bars between the legs as described in U.S. Pat. No. 6,082,813 to Chen and U.S. Pat. No. 5,984,406 to Lee. Chen""s chair advantageously collapses to a relatively compact form. However, the position of the back support is limited to a vertical position, which may not be comfortable over a prolonged period. On the other hand, Lee""s chair provides an angled backrest, although it lacks a seat support entirely.
In addition to the problems of the collapsible chairs mentioned above, all or almost all of the known collapsible chairs suffer from a common disadvantage in that the seat will loose tension once the seat supports the weight of a person. Moreover, where known chairs are collapsible in a single motion, such chairs do typically fail to provide a seat support rod onto which the seat can be tensioned. Alternatively, where known chairs have a pair of seat support rods, such chairs generally require at least two folding motions (e.g., one motion in which the seat is folded upwards followed by one motion in which the seat is folded in a side-to-side movement). Therefore, there is a need to provide improved methods and apparatus for collapsible chairs.
The present invention is directed to a collapsible chair that can be collapsed in a single motion. In particular, contemplated collapsible chairs have a pair of front legs, a pair of rear legs, a pair of back support rods, a seat, and a cross brace with a first and second end, the first end coupled to one of the rear legs, and the second end slidably coupled to one of the back support rods via a coupling element. In contemplated collapsible chairs, the seat is coupled to the pair of rear legs, and the coupling element further slidably couples one of the front legs to the one of the back support rods, wherein the front legs, the rear legs, the cross brace, and the back support rods are coupled in a manner such that the chair collapses in a single movement in which the front legs approximate each other when the seat pivots towards the back support rods.
In one aspect of the inventive subject matter, at least one of the pair of front legs is rotatably coupled to at least one of the pair of rear legs, and contemplated collapsible chairs may further comprise a second cross brace with a first and second end, the first end coupled to one of the front legs, and the second end coupled to one of the rear legs. It is further contemplated that coupling elements may further rotatably couple one of the rear legs and one of the front legs to one of the back support rods.
In another aspect of the inventive subject matter, a backrest is coupled to the pair of back support rods, and the seat is a tensioned seat, and it is generally preferred that the backrest is continuous with the tensioned seat and comprises a weather resistant fabric (e.g., Nylon). It is also preferred that at least one of the pair of front legs, the pair of rear legs, and the back support rods is manufactured from aluminum.
In a further aspect of the inventive subject matter, a method of imparting collapsibility into a chair comprise one step in which a pair of front legs, a pair of rear legs, a pair of back support rods, a seat, a coupling element, and a cross brace with a first and second end are provided. In a further step, the second end of the cross brace is slidably coupled to one of the back support rods via the coupling element. In a still further step, one of the front legs is slidably coupled to the one of the back support rods via the coupling element, and in yet another step, a seat is coupled to the pair of rear legs, wherein the front legs, the rear legs, the cross brace, and the back support rods are coupled in a manner such that the chair collapses in a single movement in which the front legs approximate each other when the seat pivots towards the back support rods.
Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings, in which like numerals represent like components.